The enhanced low-voltage cathodoluminescent properties of spherical Y ₂O₃:Eu³⁺ phosphors coated with In ₂O₃ and its application to field-emission displays

Dispersed and spherical Y₂O₃:Eu³⁺ red phosphor particles were prepared by the urea homogeneous precipitation method. In₂O₃ nanoparticles were successfully coated on the surface of the phosphor. Phase compositions, morphologies, photoluminescence (PL) spectra, and cathodoluminescence (CL) properties of Y₂O ₃:Eu³⁺ phosphors before and after In₂O ₃ coating were examined. It was found that CL properties such as luminous efficiency, lifetime, and stability of In₂O ₃-coated phosphor screen were improved significantly, even though its PL intensity decreased compared with that of the uncoated sample. The reason is attributed to the increase of the electrical conductivity and the decrease of the charge accumulating effect. The present results prove that Y ₂O₃:Eu³⁺ phosphor coated with an appropriate amount of In₂O₃ is more suitable to the requirement for low-voltage field-emission displays.